Recently, in the current mobile terminals (for example, a notebook computer or a mobile phone), generally a plurality of networks are available for connection. At the same time, with the spread of netbooks and advanced mobile terminals, the mobile terminal may also be provided with connections including wire network, wireless network, such as WiFi, the 2nd Generation mobile communication technology and/or the 3rd Generation, and the like. One mobile terminal may generally only use one network as its default connection, but this network connection may not be always available. In practical applications, a user often accesses a WiFi network and establishes a connection, but the user has to accomplish a further security authentication before using the network connection normally, although the WiFi network may operate at this time (for example, in a WiFi hot spot at airport and hotel). Sometimes, the network transmission of the mobile terminal may often interrupt although the mobile terminal has connected to the WiFi network, because too many mobile terminals connect at the same time.
The current Universal Access Method (UAM) generally utilizes a roaming mechanism allowed by wireless operators. That is, a roaming user may access the network by inputting his/her username and password through a login interface, when he/she accesses a homepage using a web browser. However, the UAM needs not only lots of local devices to settle the switch problem among various network connections, for example, a roaming problem between 3G and WiFi, which demands a support from all of the mobile terminals, but also a close cooperation among the operators in the various network connections, which would bring a high cost for switching among the network connections and take a long period for switching among the network connections, thus the switch efficiency is low.